9mm AR SBR questions

[rouchna]

I've seen handguards blow apart from things like that BUT they were 5.56.

I wouldn't do it, but you might get away with no damage. May.

Well sh*t. I was hoping for a different answer. Do they make a short extension that will allow me to extend the barrel a bit and use the brake? Thanks Chad.

 

[mtlcafan79]

What's the ID on that rail? If you can fit 1.2" then: http://www.kakindustry.com/ar-15-pa...-2-36-threads/kak-industry-slim-flash-can-9mm

 

[erwos]

I wouldn't do it, but you might get away with no damage. May.

My thought, too. This kind of thing falls into the realm of "play stupid games, win stupid prizes". Also very unclear to me why you'd want to brake a 9mm AR, vs using a flash hider or comp. Recoil is just not that heavy.

 

[rouchna]

What's the ID on that rail? If you can fit 1.2" then: http://www.kakindustry.com/ar-15-pa...-2-36-threads/kak-industry-slim-flash-can-9mm

Thank you. This should work well.

My thought, too. This kind of thing falls into the realm of "play stupid games, win stupid prizes". Also very unclear to me why you'd want to brake a 9mm AR, vs using a flash hider or comp. Recoil is just not that heavy.

My purchasing a brake has nothing to do with recoil. I was looking for either a FH, or a brake that I could put on while I wait for my suppressor. I found this one and it seemed to fit the bill. I'm just looking for a temporary way to have a little fun with this until my Form 4 is approved.

 

[erwos]

Ah, alright. Still, flash can is a good idea.

 

[rouchna]

Yes, it is what I have in mine.

Question for you. Did you have any issues with the bolt not unlocking easily? I'm using a CMMG MK9 ramped bolt and a BCM Charging handle. When trying to pull the charging handle, I have to use a lot of force to unlock the bolt. Any advice?

Thanks.

As this build is coming together, I'm sure I will have more questions so I thank you, and everyone else for your help in advance.

 

[clandestine]

These guns don't lockup. If your fighting something, then something wrong. It's just straight blowback. The only thing that the bolt overcomes is the recoil spring and the hammer being cocked. What FCG are you using?

 

[rouchna]

These guns don't lockup. If your fighting something, then something wrong. It's just straight blowback. The only thing that the bolt overcomes is the recoil spring and the hammer being cocked. What FCG are you using?

I'm using a Spikes FCG. The bolt travels back and forth just fine when separated from the lower. However, once it's assembled, that first pull of the charging handle is a bitch.

 

[clandestine]

I'm using a Spikes FCG. The bolt travels back and forth just fine when separated from the lower. However, once it's assembled, that first pull of the charging handle is a bitch.

Sounds like the hammer is binding in the lower, the hamme tail is bottoming out on the disconnector, or the hammer is binding as it's rotated into the carrier recession as it rests on the firing pin.

 

[rouchna]

Sounds like the hammer is binding in the lower, the hamme tail is bottoming out on the disconnector, or the hammer is binding as it's rotated into the carrier recession as it rests on the firing pin.

I thought a regular FCG was good to go with a ramped bolt. I have 2 geissele triggers from my other rifles I can try. Do you think it's worth trying it?

 

[clandestine]

I thought a regular FCG was good to go with a ramped bolt. I have 2 geissele triggers from my other rifles I can try. Do you think it's worth trying it?

They are OK but they don't always play well without some minor tweaks. Yes, it's a good idea to try another FCG to try and diagnose where the issue is. If need be I can do a video chat and we can troubleshoot one night.

 

[rouchna]

They are OK but they don't always play well without some minor tweaks. Yes, it's a good idea to try another FCG to try and diagnose where the issue is. If need be I can do a video chat and we can troubleshoot one night.

I will swap out the FCG tomorrow and see if that fixes the issue. If not, I will take you up on your very kind offer. Thank you

 

[dontpanic]

I will swap out the FCG tomorrow and see if that fixes the issue. If not, I will take you up on your very kind offer. Thank you

The hammer face needs a more rounded corner to work well. I ended up getting a POF trigger . This was a recommendation to me by the guys at Gun Connection.

My pistol should be together in the next week or so. I'll let you know soon if it works well.

Good luck on your build

 

[rouchna]

I swapped out my trigger for a Geissele and I was still having the same issue. After talking to a friend (TYfromMD), he recommended I take the bolt catch out and see if the problem still persists. Well, it worked. Without the bolt catch installed, the bolt comes right back as it should without using any force. Have any of you guys encountered this issue? Here is a picture of the lower with the bolt catch still installed. I'm still trying to figure out where it's catching. I also need to find a different bolt catch. Thoughts?

 

[clandestine]

That's a good catch from TY.

Is it the internal 9mm catch or the one you activate from the outside? One option may be to remove those parts and put in a colt 9mm catch if the internal catch tab is the cause. Brownells carries the 9mm catch. What lower is that? I assume it uses colt pattern mags right?

 

[rouchna]

That's a good catch from TY.

Is it the internal 9mm catch or the one you activate from the outside? One option may be to remove those parts and put in a colt 9mm catch if the internal catch tab is the cause. Brownells carries the 9mm catch. What lower is that? I assume it uses colt pattern mags right?

It's the one you activate from the outside. The lower is a QuarterCircle10 (Formerly DDLES) that uses the Colt pattern mags. I've searched online but couldn't find a similar issue. I have an email out to QC10 to see if they've heard of similar problems.

By the way, I really appreciate you responding to my never ending questions.

 

[clandestine]

Always happy to help my friend. We will get this working.

If DDLES does not reply we can figure out something.

 

[TyFromMD]

Glad I could help!

 

[ar15dave]

My 9mm build has a CMMG ramped bolt. No issues what so ever. I use a standard DPMS LPK and never had an issue.

Here is a pic of my upper. It is an LRM-169 running a CMMG ramped bolt. I can put this on any AR15/M16 lower I want and it rocks.

Dave

 

[SWO Daddy]

Another question for you fine folks. I bought a 9mm muzzle brake so that I'm able to shoot this while waiting for my suppressor to be approved. As you can see by the photo below, one of the ports on the brake is inside the handguard. Now I know that 9mm doesn't produce a lot of flash, but should I be worried about ruining my handguard? A friend of mine on the forum brought it up and it's got me thinking. I'm obviously going to put a handstop so that I don't ruin my hand



Let me know your thoughts. Thanks.

Ehhh...I'd be a little nervous. Here's an AR (556) which broke a fortis rail:

Thread: http://www.m4carbine.net/showthread.php?135012-I-blew-up-my-rail

Have you thought about putting a Noveske Pig on there instead? Honestly, on a 9mm, that may be more useful anyways....